Efficient signaling based on associations of configuration parameters

ABSTRACT

Described are methods, devices and systems for addresses efficient signalling of the association between downlink signals (e.g. SS/PBCH (synchronization signal/physical broadcast channel) blocks (SSBs) or CSI-RS (channel-state information reference signal)) and physical random access channel (PRACH) resources. In some embodiments, the “number of SSBs per PRACH resource” parameter value is associated with the number of frequency multiplexed PRACH resources and/or the number of symbols in the PRACH preamble format. Embodiments of the disclosed technology enable more flexible random access configurations and allow a wider range of network implementations.

CROSS-REFERENCE TO RELATED APPLICATION

This patent document is a continuation of and claims benefit of priorityto International Patent Application No. PCT/US2019/013403, filed on Jan.12, 2019, which claims the benefit of priority to U.S. ProvisionalPatent Application No. 62/617,073, filed on Jan. 12, 2018. The entirecontent of the aforementioned patent application is incorporated byreference as part of the disclosure of this patent document.

TECHNICAL FIELD

This document relates to systems, devices, and techniques for wirelesscommunications.

BACKGROUND

Wireless communication technologies are moving the world toward anincreasingly connected and networked society. The rapid growth ofwireless communications and advances in technology have led to greaterdemand for capacity and connectivity. Other aspects, such as energyconsumption, device cost, spectral efficiency, and latency are alsoimportant to meeting the needs of various communication scenarios. Incomparison with the existing wireless networks, next generation systemsand wireless communication techniques need to support much deepercoverage and huge number of connections.

SUMMARY

This document relates to methods, systems, and devices for efficientsignaling based on associations of downlink and uplink resources.Embodiments of the disclosed technology reduce the number ofconfiguration bits needed to identify physical random access channel(PRACH) resources. This is achieved by using the association betweendownlink signals and other signaling parameters to identify the PRACHresources, and enables more flexible random access configurations andallows a wider range of network implementations.

In one exemplary aspect, a wireless communication method is disclosed.The method includes receiving, from a network node, at least onesignaling parameter, receiving a plurality of downlink signals,generating measurements based on at least one of the plurality ofdownlink signals, selecting one of the plurality of downlink signalsbased on the measurements, identifying a set of random access resourcesand a set of random access preamble indexes associated with the one ofthe plurality of downlink signals based on the at least one signalingparameter, selecting a random access resource from the identified set ofrandom access resources and a random access preamble index from theidentified set of random access preamble indexes, and transmitting apreamble with the selected random access preamble index on the selectedrandom access resource.

In another exemplary aspect, a wireless communication method isdisclosed. The method includes transmitting, to a wireless device, arandom access configuration comprising at least one signaling parameter,transmitting a plurality of downlink signals, detecting a preamble witha random access preamble index on a random access resource, andtransmitting, in response to receiving the preamble, a random accessresponse, wherein the random access resource and the random accesspreamble index are selected from a set of random access resources and aset of random access preamble indexes, respectively, and wherein theselection is associated with one of the plurality of downlink signalsbased on the at least one signaling parameter.

In yet another exemplary aspect, a wireless communication method isdisclosed. The method includes receiving, from a network node, aninformation element indicating a first parameter and a second parameter,selecting a random access resource based on the first parameter,selecting a random access preamble index based on the second parameter,wherein a value of the second parameter does not exceed a maximum valuefor the second parameter based on a relationship between the first andsecond parameter, and transmitting a preamble with the selected randomaccess preamble index on the selected random access resource.

In yet another exemplary aspect, a wireless communication method isdisclosed. The method includes transmitting, to a wireless device, aninformation element indicating a first parameter and a second parameter,transmitting a plurality of downlink signals, detecting a preamble witha random access preamble index on a random access resource, andtransmitting, in response to receiving the preamble, a random accessresponse, wherein the random access resource and the random accesspreamble index are selected from a set of random access resources and aset of random access preamble indexes, respectively, wherein theselection is associated with one of the plurality of downlink signalsbased on the first parameter and the second parameter, and wherein avalue of the second parameter does not exceed a maximum value for thesecond parameter based on a relationship between the first and secondparameter.

In yet another exemplary aspect, the above-described methods areembodied in the form of processor-executable code and stored in acomputer-readable program medium.

In yet another exemplary embodiment, a device that is configured oroperable to perform the above-described methods is disclosed.

The above and other aspects and their implementations are described ingreater detail in the drawings, the descriptions, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a base station (BS) and user equipment (UE)in wireless communication, in accordance with some embodiments of thepresently disclosed technology.

FIG. 2 shows an exemplary association of SS/PBCH (synchronizationsignal/physical broadcast channel) blocks (SSBs) and physical randomaccess channel (PRACH) resources.

FIG. 3 shows another exemplary association of SSBs and PRACH resources.

FIG. 4 shows yet another exemplary association of SSBs and PRACHresources.

FIG. 5 shows yet another exemplary association of SSBs and PRACHresources.

FIG. 6 shows yet another exemplary association of SSBs and PRACHresources.

FIG. 7 shows yet another exemplary association of SSBs and PRACHresources.

FIG. 8 shows yet another exemplary association of SSBs and PRACHresources.

FIG. 9 shows yet another exemplary association of SSBs and PRACHresources.

FIG. 10 shows an example of a wireless communication method carried outon a wireless device (or user equipment).

FIG. 11 shows an example of a wireless communication method carried outon a network node (or gNB or base station).

FIG. 12 is a block diagram representation of a portion of an apparatusthat may implement a method or technique described in this patentdocument.

DETAILED DESCRIPTION

Next generation (5G) wireless communication systems may use an advancedrandom access scheme, for example, to support the use of beamformingalso during the random access. Such a scheme will support various basestation (BS) and user equipment (UE) implementations in terms ofbeamforming, e.g. digital, hybrid or analog beamforming implementationsas well as multi-TRP (transmission/reception point) implementations.

A part of the random access procedure is that the UE measures downlink(DL) signals, for example SS/PBCH (synchronization signal/physicalbroadcast channel) blocks (SSBs) and/or CSI-RS (channel-stateinformation reference signal). The measurement results, e.g. RSRP(reference signal received power) are then used to select a subset ofPRACH (physical random access channel) resources and/or a subset ofPRACH preamble indices.

FIG. 1 shows an example of a wireless communication system that includesa base station (BS) 120 and one or more user equipment (UE) 111, 112 and113. In some embodiments, the base station may broadcast a random accessconfiguration that includes a signaling parameter, and then transmitdownlink signals (141, 142, 143) to the UEs. Each of the UEs receivesthis information and may transmit selected preamble (131, 132, 133) on aselected PRACH resource, wherein the selection is based on anassociation between the downlink signals and the signaling parameter.

For example, the DL signal with highest RSRP is used to select PRACHresource and/or preamble index. In some cases, it is up to the UE selectwhich DL signal to use for selecting PRACH resource and/or preambleindex. In some cases, e.g. new radio (NR), the UE may select any of theDL signals (e.g. SSBs) with a measurement result above a threshold,which may be configurable.

Some embodiments of the disclosed technology described in this patentdocument use SSB as an example of a downlink (DL) signal. However, theseembodiments are also compatible with other sets of DL signals, such as aset of configured CSI-RS. The embodiments are also compatible with the“actually transmitted SSBs” (“present SSBs”, which may be a subset ofall SSBs. The subset of actually transmitted SSBs can be indicated inbroadcast system information (SI) (e.g. system information block 1(SIB1) in NR) and/or with dedicated (UE specific) signaling, e.g. RRCsignaling. Actually transmitted SSBs may be configured with theparameters SSB-transmitted-SIB1, InOneGroup, groupPresence and/orSSB-transmitted, which use one or more bitmaps to indicate actuallytransmitted SSBs.

A PRACH resource is a time-frequency resource in which a UE can transmita PRACH preamble according to a preamble format. In some embodiments, aPRACH preamble may consist of one or more symbols (or sequences, e.g.Zadoff-Chu sequences), e.g. OFDM (orthogonal frequency divisionmultiplexing) symbols. NR, for example, supports both single symbolPRACH preamble formats and formats with multiple symbols (or sequences),e.g. 2, 4, 6 and 12 symbols (or sequences). Different PRACH resourcesmay be multiplexed in frequency and/or in time. In some contexts, aPRACH resource is called RACH occasion (RO), PRACH occasion or PRACHtransmission occasion.

The mechanism by which the UE selects an SSB to select a subset of PRACHresources and/or preamble indices is called association (also calledmapping). In the association framework, each of the SSBs that the UE mayselect is associated with a subset of PRACH resources and/or a subset ofpreamble indices. In some embodiments, the association may beconfigurable by the network, for example in SI, e.g. SIB1, and/or withdedicated (UE specific) signaling, e.g. RRC signaling.

In some embodiments, a subset of PRACH resources may be a subset of aset of PRACH resources that are configured using a PRACH resourceconfiguration. For example, such a configuration of a set of PRACHresources can be done via a PRACH configuration index (e.g. calledprach-ConfigurationIndex or PRACHConfigurationIndex in thespecification), as in LTE and NR.

In some embodiments, a subset of preamble indices may be a subset of theset of the indices of the PRACH preambles (preamble sequences) availablein a PRACH resource. The set of indices available in a PRACH resourcemay be limited by various configurations such as a configuration ofrestricted set, e.g. restricted set type A or type B, cyclic shiftconfiguration, e.g. zeroCorrelationZoneConfig in NR.

For an efficient configuration (e.g. few configuration bits) of theassociation between SSBs and subsets of PRACH resources and/or preambleindices, it can be defined by specifying a few simple association rulesand a few configuration parameters. For some embodiments of NR, thefollowing rules may be implemented for contention-based random access(CBRA):

(1) Association of one SSB to one PRACH resource is supported, e.g.different SSBs are associated with disjoint subsets of PRACH resources.

(2) Association of many SSBs to one PRACH resource is supported, e.g.different SSBs can be associated with overlapping subsets of PRACHresources.

(3) Association of one SSB to many consecutive PRACH resources, e.g. oneSSB is associated to all frequency multiplexed PRACH resources in onetime instance.

(4) Each SSB is associated with the same number of PRACH preambleindices, e.g. the associated preamble subsets are of equal size.

(5) The subset of preamble indices associated with an SSB areconsecutive.

(6) The SSBs are consecutively mapped to subsets of PRACH resourcesand/or subsets of preamble indices in the order of:

(6.1) Increasing preamble index in a PRACH resource,

(6.2) Increasing frequency multiplexed PRACH resource, and

(6.3) Increasing time multiplexed PRACH resource (e.g. first toconsecutive PRACH resources in a slot and then to PRACH resources insubsequent slots).

Frequency Multiplexing

In some embodiments, the number of frequency multiplexed PRACH resources(denoted F for brevity) is a signaling parameter that may be associatedwith the “number of SSBs per PRACH resource” parameter value. In someembodiments, the parameter is denoted prach-FDM, and may be configuredas a 2-bit parameter.

In some embodiments, the number of frequency multiplexed PRACH resourcesis the same for each time instance in which PRACH resources areconfigured. In some embodiments, the number of frequency multiplexedPRACH resources is different in different time instances in which PRACHresources are configured.

For example if both PRACH resources for CBRA and separate PRACHresources for CFRA are configured in some time instances while onlyPRACH resources for CBRA or separate PRACH resources for CFRA areconfigured in other time instance. In some embodiments, the number offrequency multiplexed PRACH resources for CBRA is the same for each timeinstance in which PRACH resources for CBRA are configured in a cell.

PRACH Preamble Formats

In various embodiments, different preamble formats can be configured. Insome embodiments, a preamble format corresponds to a set of parameters,for example one or more of the following:

(1) a sequence length (e.g. lengths 139 or 839),

(2) a cyclic prefix (CP) duration,

(3) the number of times the sequence is repeated within the preamble(denoted K for brevity), not counting the CP (and/or the duration of thepreamble excluding the CP),

(4) a subcarrier spacing, and

(5) a bandwidth.

In various embodiments, the preamble format or a part of the preambleformat is jointly indicated with a PRACH resource configuration, e.g.using a PRACH configuration index. In some embodiments, the preambleformat or a part of the preamble format is configured separately fromthe PRACH resource configuration.

Association Configuration Parameters

Embodiments of the disclosed technology are described in the context ofrandom access configurations for contention-based random access (CBRA).These embodiments may be applied to random access configurations forcontention free random access (CFRA).

In some embodiments, the association between SSBs and subsets of PRACHresources and/or subsets of preamble indices is achieved by configuringthe two parameters:

(1) The number of preambles per SSB per PRACH resource (denoted P forbrevity). In some embodiments, the parameter is denotedCB-preambles-per-SSB, and may be configured as a 4-bit parameter, and

(2) The number of SSBs that are associated with a PRACH resource(denoted S for brevity). In some embodiments, the parameter is denotedSSB-per-rach-occasion, and may be configured as a 3-bit parameter.

Note that S can be both greater than 1 or less than 1, e.g. S=N or S=1/Nwhere N is a positive integer such as N=2, 4, 8, in various embodiments.

For example, an S greater than 1, e.g. S=2, means that 2 different SSBsare associated with the same PRACH resource. Such a configuration isuseful for example when the different SSBs associated with the same RACHresource are configured to be associated with different (e.g. disjoint)sets of preamble indices.

For example, an S less than 1, e.g. S=½, means that one SSB isassociated with 2 consecutive PRACH resources. Such a configuration isuseful for example when there are multiple frequency multiplexed PRACHresources in one time instance, but a single beam (corresponding to asingle SSB) can be used per time instance.

Example Associations

FIGS. 2-8 illustrate various embodiments with a few different PRACHresource allocations and associations with 8 SSBs. The boxes in thefigures represent PRACH resource, i.e. time-frequency resource in whicha PRACH preamble can be transmitted. The text in the boxes, e.g. “SSB 0”and “SSB 1” represents that SSB 0 and SSB 1 are associated with thePRACH resource. When all SSBs have been associated with PRACH resources,the association wraps around and continues with SSB0 in the next PRACHresource.

FIG. 2 shows an example wherein two SSBs are associated with a PRACHresource, i.e. S=2. Based on the PRACH resource configuration, the SSBsare consecutively associated with the PRACH resources. All SSBs areassociated with PRACH resources in two time instances with PRACHresources.

FIG. 3 shows an example wherein two SSBs are associated with a PRACHresource, i.e. S=2. Based on the PRACH resource configuration, the SSBsare consecutively associated with the PRACH resources. All SSBs areassociated with PRACH resources in one time instance with PRACHresources.

FIG. 4 shows an example wherein 8 SSBs are associated with a PRACHresource, i.e. S=8. Based on the PRACH resource configuration, the SSBsare consecutively associated with the PRACH resources. All SSBs areassociated with PRACH resources in one time instance with PRACHresources.

FIG. 5 shows an example wherein one SSBs are associated with a PRACHresource, but each SSB is associated with two consecutive PRACHresources, i.e. S=½. Based on the PRACH resource configuration, the SSBsare consecutively associated with the PRACH resources. All SSBs areassociated with PRACH resources in 8 time instances with PRACHresources.

FIG. 6 shows an example wherein one SSBs are associated with a PRACHresource, but each SSB is associated with two consecutive PRACHresources, i.e. S=½. Based on the PRACH resource configuration, the SSBsare consecutively associated with the PRACH resources. All SSBs areassociated with PRACH resources in 16 time instances with PRACHresources.

FIG. 7 shows an example wherein one SSBs are associated with a PRACHresource, but each SSB is associated with four consecutive PRACHresources, i.e. S=¼. Based on the PRACH resource configuration, the SSBsare consecutively associated with the PRACH resources. All SSBs areassociated with PRACH resources in 16 time instances with PRACHresources.

FIG. 8 shows an example wherein one SSBs are associated with a PRACHresource, but each SSB is associated with 8 consecutive PRACH resources,i.e. S=⅛. Based on the PRACH resource configuration, the SSBs areconsecutively associated with the PRACH resources. All SSBs areassociated with PRACH resources in 1 time instances with PRACHresources.

Signaling of the Number of SSBs Per PRACH Resource (S)

Based on the examples shown in FIGS. 2-8, it is clear that it may benecessary to support a wide range of parameter values for S. In theexamples, the values S={8, 2, ½, ¼, ⅛} were shown. However, depending onthe maximum number of frequency multiplexed PRACH resources, the maximumnumber of consecutive time instances to which the same SSB is associatedwith all PRACH resources and the maximum number SSBs associated with thesame PRACH resource, a much wider range of parameter values may beneeded.

For example, in an embodiment with up to 8 frequency multiplexed PRACHresources and up to 32 SSBs associated with the same PRACH resource, itmight be necessary to support the following parameter values for S:S={32, 28, 25, 24, 21, 20, 18, 16, 15, 14, 12, 10, 9, 8, 7, 6, 5, 4, 3,2, 1, ½, ⅓, ¼, ⅕, ⅙, 1/7, ⅛}, which is 28 values (needs 5 bits).

One potential drawback when supporting a large value range for S is thereliance on the assumption that the parameter values are fixed in aspecification. In some embodiments of the disclosed technology, a moreefficient signalling of S is designed by exploiting that some values ofS are only useful in some scenarios, in various embodiments. This mayresult in needing fewer bits to indicate S. Alternatively, given acertain number of bits used to indicate S, the value range can beexpanded and more flexible and efficient association can be configured.

In some embodiments, the value of S is made to depend on the number offrequency multiplexed PRACH resources (F).

In some embodiments, the value of S is made to depend on the number ofsymbols (or sequences) in the configured PRACH preamble format (K).

In some embodiments, the value of S is made to depend on both the numberof frequency multiplexed PRACH resources and the number of symbols (orsequences) in the configured PRACH preamble format.

Example Embodiments of S Depending on F

In an example, let S′ denote the parameter that is signalled, in a SI(e.g. SIB1) and/or with dedicated signalling (e.g. in a handovercommand), in a random access configuration. In some embodiments, S′ isthe RRC parameter SSB-per-RACH-occasion, which is 3 bits in someembodiments. In some embodiments, the encoding and/or value range of Sand/or S′ are specified using ASN.1, for example using the INTEGER { }or ENUMERATED { } types, in various embodiments. For example S′=INTEGER{0 . . . 31} or S=ENUMERATED {s32, s28, . . . , s1over7, s1over8}, wheres32 corresponds to 32, s1over7 corresponds to 1/7 etc.

In some embodiments, the number of values for S′ is the same as thenumber of values for S, in some cases including some reserved values.For example, if the 28 different vales for S in the example above areneeded, then the 5-bit S′ could have values 0-31 with the values 0-27each corresponding to one of the values of S={32, 28, . . . , 1/7, ⅛}.The four remaining values of S′ could be reserved for future use. Thisis summarized in Table 1.

TABLE 1 S' (5 bits)  0  1 . . . 27 28 . . . 31 S (28 values) 32 28 . . .1/8 reserved . . . reserved

In various embodiments, the number of SSBs associated with a PRACHresource (S) is based on both the signalled S′ and the number offrequency multiplexed PRACH resources (F). Note that F is signalledseparately in various embodiments. In various embodiments, the value ofS can be obtained from a table, where the values of S′ and F can be usedto select one table entry. An embodiment is illustrated in Table withexemplary values.

TABLE 2 S′ (3 bits): 0 1 . . . 6 7 F = 1 S = 32 S = 25 . . . S = 2 S = 1F = 2 S = 28 S = 24 . . . S = 1 S = 1/2 . . . . . . . . . . . . . . .. .. . F = 8 S = 8 S = 4 . . . S = 1/4 S = 1/8

In various embodiments, the value range of F depends on the PRACHpreamble format, for instance as configured by a PRACH configurationindex. In some embodiments, the value range of F depends on one or moreof the PRACH preamble bandwidth, PRACH subcarrier spacing, PRACHsequence length, PRACH configuration index. In some embodiments, thevalue range of F is defined in a table such that the maximum value for F(F_(max)) is such that F_(max) frequency multiplexed PRACH resources,e.g. consecutively or non-consecutively, fit into a maximum bandwidth ofan initial active uplink bandwidth part. In some embodiments, themaximum bandwidth of an initial active uplink bandwidth part depends onthe carrier frequency, i.e. different frequency ranges may havedifferent maximum bandwidths. In some embodiments, the maximum bandwidthof an initial active uplink bandwidth part is equal to or less than theminimum required UE UL transmission bandwidth, which may be different indifferent carrier frequency ranges.

An example embodiment is shown below, where RB=resource block,SCS=subcarrier spacing, and prach-FDM=F.

Frequency range 1 (below 6 GHz):  Long sequence with 1.25 kHz SCS:prach-FDM = {1, 2, 4, 8}   prach-FDM = 8 corresponds to 8.64 MHz (48 RBsin 15 kHz)  Long sequence with 5 kHz SCS: prach-FDM = {1, 2, 3, 4}  prach-FDM = 8 corresponds to 17.28 MHz (96 RBs in 15 kHz)  Shortsequence with 15 kHz SCS: prach-FDM = {1, 2, 4, 8}   prach-FDM = 8corresponds to 17.28 MHz (96 RBs in 15 kHz)  Short sequence with 30 kHzSCS: prach-FDM = {1, 2, 3, 4}   prach-FDM = 4 corresponds to 17.28 MHz(96 RBs in 15 kHz) Frequency range 2 (above 6 GHz):  Short sequence with60 kHz SCS: prach-FDM = {1, 2, 4, 8}   prach-FDM = 8 corresponds to69.12 MHz (96 RBs in 60 kHz)  Short sequence with 120 kHz SCS: prach-FDM= {1, 2, 3, 4}   prach-FDM = 4 corresponds to 69.12 MHz (96 RBs in 60kHz)

Example Embodiments of S Depending on K

In various embodiments, the number of SSBs associated with a PRACHresource (S) is based on both the signalled S′ and the number of numbersymbols (or sequences) in the configured PRACH preamble format (K). Forexample, the number of symbols can be 1, 2, 4, 6 or 12. Note that K canbe signalled separately in various embodiments and as a part of PRACHconfiguration index on various embodiments. In various embodiments, thevalue of S can be obtained from a table, where the values of S′ and Kcan be used to select one table entry. An embodiment is illustrated inTable 3 with exemplary values.

TABLE 3 S′ (3 bits): 0 1 . . . 6 7 K = 1 S = 4 S = 2 . . . S = ¼ S = 1/8K = 2 S = 8 S = 4 . . . S = 1/2 S = 1/4 . . . . . . . . . . . . . . . .. . K = 8 S = 32 S = 24 . . . S = 1 S = 1/2

In some embodiments, S may be associated with K since it may be moreuseful to associate many SSB with a PRACH resource if the preambleformat used in the PRACH resource has many symbols (or sequences). Forexample, the association of many SSBs to one PRACH resource is usefulwhen the base station uses beamforming but doesn't support Tx/Rx beamcorrespondence. In such scenarios, the base station may configure apreamble format with many symbols, so that the base station can performRx beam sweeping during the PRACH resource. In this case, it isadvantageous to configure many SSB to one PRACH resource association,and instead configure different (e.g. disjoint) sets of preamblesindices for different SSBs. On the other hand, when the PRACH resourceis based on a short single-symbol preamble format, the need to associatemany SSBs to a PRACH resource is lower.

Example Embodiments of S Depending on F and K

In various embodiments, the number of SSBs associated with a PRACHresource (S) is based on both the signalled S′, the number of frequencymultiplexed PRACH resources (F) and the number of number symbols (orsequences) in the configured PRACH preamble format (K). In variousembodiments, the value of S can be obtained from a table, where thevalues of S′, F and K can be used to select one table entry. In variousembodiments, the value of S can be obtained from a set of tables. Insome embodiments, one of these tables corresponds to one value of F, andthe values of S′ and K can be used to select one table entry in one ofthese tables, for example as in Table 3. In some embodiments, one ofthese tables corresponds to one value of K, and the values of S′ and Fcan be used to select one table entry in one of these tables, forexample as in Table 2.

Embodiments with an Additional Configuration Parameter (Z)

In various embodiments, an additional parameter Z for configuring theassociation between SSBs and subsets of PRACH resources and/or a subsetsof preamble indices is introduced. In some embodiments, the parameter Zindicates the number of consecutive PRACH resources (e.g. according tothe mapping order mentioned above) over which the same association(s)and/or SSBs are repeated. This repetition could be similar or the sameas when S=1/N with N being a positive integer, as described above. Invarious embodiments in which Z is used, the values of S are restrictedto S=N. It may not be necessary to include such fractional values (e.g.1/N) in S if a similar or same function is achieved with the separateparameter Z.

For example, the associations in FIG. 5 could be achieved by setting S=1and Z=2, in some embodiments. Similar embodiments for the examples shownin FIGS. 2-8 may be disclosed in a similar manner.

In some embodiments, a benefit of using a separate parameter Z toindicate the repetition is that the association of multiple SSBs to aPRACH resource can be combined with repetition greater that one.

FIG. 9 shows an example where two SSBs are associated with a PRACHresource, i.e. S=2, and each SSB is associated with two consecutivePRACH resources, i.e. Z=2. Based on the PRACH resource configuration,the SSBs are consecutively associated with the PRACH resources. All SSBsare associated with PRACH resources in 4 time instances with PRACHresources. As shown in FIG. 9, it may be possible to combine S=2 withZ=2. In the embodiments without Z, it may not be possible tosimultaneously configure S=2 and S=½.

Embodiments with a separate S and Z allow more flexible configuration ofassociations. For example, BS beamforming constraints, e.g. “hybridbeamforming implementation”, may limit the association of SSBs in a timeinstance to two SSBs. In the example of FIG. 9, only SSB 0 and SSB 1 canbe received in the first time instance with PRACH resources, only SSB 2and 3 can be received in the second time instance etc. With a singleparameter S (for F=2), the typical configuration would be S=1, i.e. SSB0 would be associated with the first frequency multiplexed PRACHresource, and SSB 1 would be associated with the second frequencymultiplexed PRACH resource. With the association in FIG. 9, the PRACHpreambles of one SSB are distributed among the frequency multiplexedPRACH resources, which can have the benefit och reduced received PRACHinterference, e.g. since the preambles associated with a particular SSBmay be received on the beam used for the SSB.

In various embodiments, the value of Z depends on the number offrequency multiplexed PRACH resources (F).

In some embodiments, Z′ is the RRC parameter configuring Z, which is 1or 2 bits in various embodiments. In some embodiments, the number ofvalues for Z′ is the same as the number of values for Z, in some casesincluding some reserved values. In some embodiments, Z=min(Z′, F), i.e.the association can be configured to be repeated on at most F PRACHresources. In some embodiments, Z=Z′. In some embodiments, Z′={0,1,2,3}corresponds to Z={1,2,3,4} or Z={1,2,4,8}.

In some embodiments, the Z′ and F parameters are mapped to Z by using atable, for example as in Table 4.

TABLE 4 F = 1 F = 2 F = 4 F = 8 Z′ = 0 Z = 1 Z = 1 Z = 1 Z = 1 Z′ = 1 Z= 1 Z = 2 Z = 2 Z = 2 Z′ = 2 Z = 1 Z = 2 Z = 4 Z = 4 Z′ = 3 Z = 1 Z = 1Z = 4 Z = 8

In various embodiments, SSBs that are associated with the same PRACHresource are associated with disjoint subsets of preamble indices. Invarious embodiments, SSBs that are associated with the same PRACHresource are associated with partly or completely overlapping subsets ofpreamble indices. In various embodiments, SSBs that are associated withthe same PRACH resource are associated with partly or completelyoverlapping subsets of preamble indices.

In some embodiments, some of the entries in the table indicate that SSBsassociated with the same PRACH resource (if any) are associated withdisjoint preamble subsets. In some embodiments, some of the entries inthe table indicate that SSBs associated with the same PRACH resource (ifany) are associated with partly or completely overlapping preamblesubsets. In some embodiments, the entries indicating overlapping subsetsfurther indicate that W SSBs (associated with the same PRACH resource)are associated with (partly or completely) overlapping preamble subsets.In some embodiments, W is equal to S. In some embodiments, differententries in the table correspond to different W. For instance, differentvalues of Z′ correspond to W=S, W=floor(S/2), W=floor(S/4), or W=S,W=ceil(S/2), W=ceil(S/4), where floor( ) and ceil( ) round down and up,respectively. Various embodiments of the disclosed technology in thecontext of this framework are shown, with exemplary values (e.g. thevalue range of F), in Table 5 and Table 6.

TABLE 5 F = 1 F = 2 F = 4 F = 8 Z′ = 0 Z = 1 (disjoint) Z = 1 (disjoint)Z = 1 (disjoint) Z = 1 (disjoint) Z′ = 1 Z = 1, W = S Z = 2 (disjoint) Z= 2 (disjoint) Z = 2 (disjoint) Z′ = 2 Z = 1, Z = 2, W = S Z = 4(disjoint) Z = 4 (disjoint) W = floor(S/2) Z′ = 3 Z = 1, Z = 1, W = S Z= 4, W = S Z = 8 (disjoint) W = floor(S/4)

TABLE 6 F = 1 F = 2 F = 4 F = 8 Z′ = 0 Z = 1 (disjoint) Z = 1 (disjoint)Z = 1 (disjoint) Z = 1 (disjoint) Z′ = 1 Z = 1, W = S Z = 2 (disjoint) Z= 2 (disjoint) Z = 2 (disjoint) Z′ = 2 Z = 1, W = S Z = 2, W = S Z = 4(disjoint) Z = 4 (disjoint) Z′ = 3 Z = 1, W = S Z = 1, W = S Z = 4, W =S Z = 8 (disjoint)

In Tables 5 and 6, for the entries marked (disjoint), the different SSBsassociated with the same PRACH resource are associated with disjointsubsets of preamble indices. This means that for a particular preambleindex in a particular PRACH resource, it is associated with no more thanone SSB.

In Tables 5 and 6, for the entries not marked with (disjoint), SSBsassociated with the same PRACH resource are to various extent associatedwith overlapping preamble subsets. For the entries marked W=S, S SSBsthat are associated with the same PRACH resource are associated to(partly or fully) overlapping subsets of preamble indices. For theentries marked W=floor(W/x), (with x=2,4 for example), a set of W SSBsthat are associated with the same PRACH resource are associated to(partly or fully) overlapping subsets of preamble indices. A second setof S-W SSBs are associated to subsets of preamble indices disjoint tothe subsets associated with the first set of SSBs. However, SSBs in thesecond set may be associated to overlapping subsets of preamble indicesamong themselves. For example, if S=4 and W=S/2=2, then two sets of 2SSBs each are associated with overlapping subsets of preamble indices,but SSBs in different sets are associated with disjoint(non-overlapping) subsets of preamble indices. In various embodiments,the size of those subsets are given by the number of preambles per SSBper PRACH resource (P).

Example Embodiments of S Depending on the Number of Actually TransmittedSSBs (L)

In various embodiments, the value range of the parameter “the number ofSSBs per PRACH resource” is fixed in the specification, for exampleS={1,2,3,4,8,12,16}. In various embodiments, the values of S depend onthe number of actually transmitted SSBs, which is separately configuredin some embodiments. The number of actually transmitted SSBs is denotedL for brevity. It is beneficial if the number of SSBs associated perPRACH resource is a factor of the total number of actually transmittedSSBs since then the actually transmitted SSBs are associated with aninteger number of PRACH resources. In some embodiments, this may allowfor the most efficient use of PRACH resources.

An example embodiment of value ranges for S for different L is shown inTable 7.

TABLE 7 Values of S: L = 8  1 2 3 4 5  6  7  8 L = 15 1 3 5 6 9 10 12 15. . . L = 64 1 2 3 4 8 16 32 64

In various embodiments, a subset of the values of S are fixed in thespecification, e.g. 1, 4, 8, while other values depend on L. In thatcase, a table would only list the values that depend on L in someembodiments. An example embodiment is given in Table 8 in which onlypositive integer S are listed. The values marked with ‘*’ are “reservedvalues” in some embodiments.

TABLE 8 Values of S: L = 1  1  1*  1*  1*  1*  1*  1*  1* L = 2   2  2* 2*  2*  2*  2*  2* L = 3   3  3*  3*  3*  3*  3*  3* L = 4   2  4  4* 4*  4*  4*  4* L = 5   5  5*  5*  5*  5*  5*  5* L = 6   2  3  6  6* 6*  6*  6* L = 7   7  7*  7*  7*  7*  7*  7* L = 8   2  4  8  8*  8* 8*  8* L = 9   3  6  9  9*  9*  9*  9* L = 10  2  4  5 10 10* 10* 10* L= 11 11 11* 11* 11* 11* 11* 11* L = 12  2  4  6  8 12 12* 12* L = 13 1313* 13* 13* 13* 13* 13* L = 14  2  7  7*  7*  7*  7*  7* L = 15  2  3  510 15 15* 15* L = 16  2  4  8 16 16* 16* 16* . . . L = 64  2  4  8 16 3264 64*

In various embodiments, a subset of the values of S are defined suchthat they are the positive integer values such that A*S*F=L*B for somepair of positive integers A and B. In some embodiments, S is limited tobe at most L. For example, for F=4 and L=16, S can have the values 1, 2,4, 8, 16, corresponding to {A,B}={4,1}, {A,B}={2,1}, {A,B}={1,1},{A,B}={1,2}, {A,B}={1,4}, respectively.

In various embodiments, the values of S, including fractional S=1/N withN being positive integer, depend on L. An example is shown in Table 9.

TABLE 9 Values of S: L = 1  1  1*  1*  1*  1* 1/8 1/4 1/2 L = 2   2  2* 2*  2* 1/8 1/4 L = 3   3  3*  3*  3* 1/8 1/4 L = 4   2  4  4*  4* 1/81/4 L = 5   5  5*  5*  5* 1/8 1/4 L = 6   2  3  6  6* 1/8 1/4 L = 7   7 7*  7*  7* 1/8 1/4 L = 8   2  4  8  8* 1/8 1/4 L = 9   3  6  9  9* 1/81/4 L = 10  2  4  5 10 1/8 1/4 L = 11 11 11* 11* 11* 1/8 1/4 L = 12  2 4  6 12 1/8 1/4 L = 13 13 13* 13* 13* 1/8 1/4 L = 14  2  7  7*  7* 1/81/4 L = 15  2  3  5 10 1/8 1/4 L = 16  2  4  8 16 1/8 1/4 ... L = 64  2 4  8 16 32 64

In some embodiments, the number of actually transmitted SSBs is aproduct of two positive integers, i.e. L=C*D, e.g. when the actuallytransmitted SSBs are indicated using two bitmaps where one bitmapindicates the actually transmitted SSBs in a group (of SSBs) and thesecond bitmap indicates the transmitted groups, with the assumption thatthe same number of SSBs is actually transmitted in each transmittedgroup.

For example, if the each of the two bitmaps is 8 bits, then the numberof actually transmitted SSBs (as indicated by the two bitmaps) is eachproduct of C={1,2,3,4,5,6,7,8} and D={1,2,3,4,5,6,7,8}, i.e. the maximumnumber is 64 SSBs. In many embodiments, the case that C=0, D=0 and/orL=0 is not feasible and can be discarded. In some cases, the actuallytransmitted SSBs are indicated by a single bitmap, e.g. 4 bits or 8bits, in which case L={1,2,3,4} or L={1,2,3,4,5,6,7,8}, respectively.

In some embodiments in which L is a product of two positive integers, Sis a function of only one of the integers C, for example the integercorresponding to the number of actually transmitted SSBs in a group. Insome embodiments in which both the two bitmap case and the single bitmapcase are used, e.g. in different ranges of carrier frequency, S is afunction of C in the two bitmap case (L is a product of C and D), e.g.in a particular range of carrier frequency, and S is a function of L inthe single bitmap case, e.g. in a particular range of carrier frequency.

In some embodiments, the range of C coincides with the range of L, e.g.C={1,2,3,4,5,6,7,8} and L={1,2,3,4,5,6,7,8}. In some embodiments, therange of L is a subset of the range of C and/or L for another frequencyrange, e.g. C={1,2,3,4,5,6,7,8} and L={1,2,3,4}. In these cases, thesame function can be used to get S from C and/or L for differentfrequency ranges. In various embodiments, the values of S include valuesthat are greater than L or C. In some embodiments, those values can beused when C is used to select S and for the cases that D>1, i.e. L isgreater than C. In some embodiments, those values of S can only be usedif L>=S. One way to express this is min(L, “S value”). An example isgiven in Table 10.

TABLE 10 Values of S: L or C = 1 1 min(L, 2) min(L, 4) min(L, 8) 1/161/8 1/4 1/2 L or C = 2 2 min(L, 4) min(L, 8) L or C = 3 3 min(L, 6)min(L, 9) L or C = 4 2 4 min(L, 8) L or C = 5 5 min(L, 10) min(L, 15) Lor C = 6 2 3 6 L or C = 7 7 min(L, 14) min(L, 21) L or C = 8 2 4 8

In various embodiments, in one frequency range, e.g. below 6 GHz, themaximum number of SSBs (e.g. 4 or 8) is equal to or less than the numberof values of S, e.g. 8, so the each feasible number of SSBs can be apart of the range of S, e.g. {1,2,3,4,5,6,7,8}.

In various embodiments, for another frequency range, e.g. above 6 GHz,the maximum number of SSBs (e.g. 64) can be larger than the number ofvalues of S, e.g. so not all feasible number of SSBs can be a part ofthe range of S. In some such embodiments, the number of actuallytransmitted SSBs is expressed through two bitmaps, as described above,with L=C*D.

For example, the number of actually transmitted SSBs above 6 GHz (asindicated in RMSI) is an integer multiple of the number of actuallytransmitted SSBs in a group (C), which for example is indicated by thebitmap in the RRC parameter InOneGroup. The number of actuallytransmitted SSBs per group can be C={1,2,3,4,5,6,7,8}. It is beneficialif the SSBs per RACH resource is an integer multiple of C since the sameset of SSBs will be associated with different RACH resources after wraparound. In some embodiments, where not all feasible number of SSB can bea part of the values of S, the values of S depend on the number ofactually transmitted SSBs in a group (C).

TABLE 11 Range of S (e.g. RRC parameter SSB-per-rach-occasion) in afrequency range (e.g. above 6 GHz) C (number of actually transmittedSSBs in a Value range of S (e.g. 3-bit SSB- group) per-rach-occasion) 11, 2, 3, 4, 5, 6, 7, 8 2 1, 2, 4, 6, 8, 10, 12, 16 3 1, 3, 6, 9, 12, 15,18, 24 4 1, 2, 4, 8, 12, 16, 24, 32 5 1, 2, 4, 5, 10, 15, 20, 25 6 1, 2,3, 6, 9, 12, 18, 24 7 1, 2, 3, 4, 7, 14, 21, 28 8 1, 2, 4, 8, 12, 16,24, 32

Example Embodiments of S Depending on F, K and/or L

In various embodiments, the values of S depend on a combination of theparameters F, K and/or L (including C and/or D).

In some embodiments, the values for S for a particular F and L (or Cand/or D) are such that each SSB associated with a PRACH resources inthe same time instance are associated with the same amount of PRACHresources and/or preamble indices.

In some embodiments, the values for S for a particular F and L (or Cand/or D) are such that the number of consecutive PRACH resources that asingle SSB can be associated to (no other SSB associated to the samePRACH resources) is limited by F.

In some embodiments, different tables are used for different carrierfrequency ranges, e.g. one table below 3 GHz, one table between 3 GHzand 6 GHz and one table equal to or above 6 GHz. These ranges correspondto 4-bit bitmap, 8-bit bitmap and 8 bit+8 bit two bitmaps (with groups),respectively.

In some embodiments, value of S is determined by a combination of C (orL) and F, as exemplified in Table 12. In some embodiments, an S of theform S=1/N (N positive integer) is included in the value range only if Fis at least N. In some embodiments, the entry otherwise corresponds toanother value on the form S═N or S=min(L,N).

TABLE 12 Values of S: L or 1 min(L, 2) min(L, 3) min(L, 4) min(L, 8) IfF ≥ 8: If F ≥ 4: ¼ If F ≥ 2: ½ C = 1 ⅛ Else: Else: Else: min(L, 5)min(L, 7) min(L, 6) L or 2 min(L, 4) min(L, 6) min(L, 8) If F ≥ 8: If F≥ 4: ¼ If F ≥ 2: ½ C = 2 ⅛ Else: Else: Else: min(L, 12) min(L, 14)min(L, 10) L or 3 min(L, 6) min(L, 9) min(L, 12) If F ≥ 8: If F ≥ 4: ¼If F ≥ 2: ½ C = 3 ⅛ Else: Else: Else: min(L, 18) min(L, 21) min(L, 15) Lor 2 4 min(L, 8) min(L, 12) If F ≥ 8: If F ≥ 4: ¼ If F ≥ 2: ½ C = 4 ⅛Else: Else: Else: min(L, 20) min(L, 24) min(L, 16) L or 5 min(L, 10)min(L, 15) min(L, 20) If F ≥ 8: If F ≥ 4: ¼ If F ≥ 2: ½ C = 5 ⅛ Else:Else: Else: min(L, 30) min(L, 35) min(L, 25) L or 2 3 6 min(L, 12) If F≥ 8: If F ≥ 4: ¼ If F ≥ 2: ½ C = 6 ⅛ Else: Else: Else: min(L, 24) min(L,30) min(L, 18) L or 7 min(L, 14) min(L, 21) min(L, 28) If F ≥ 8: If F ≥4: ¼ If F ≥ 2: ½ C = 7 ⅛ Else: Else: Else: min(L, 42) min(L, 49) min(L,35) L or 2 4 8 min(L, 16) If F ≥ 8: If F ≥ 4: ¼ If F ≥ 2: ½ C = 8 ⅛Else: Else: Else: min(L, 32) min(L, 40) min(L, 24)

In some embodiments, different tables are used for different carrierfrequency ranges, e.g. one table below 3 GHz, one table between 3 GHzand 6 GHz and one table equal to or above 6 GHz. These ranges correspondto 4-bit bitmap, 8-bit bitmap and 8 bit+8 bit two bitmaps (with groups),respectively.

In some embodiments, the table for 3 GHz and/or with 4-bit table hasfour rows corresponding to different L. In some embodiments, S valuerange (for below 3 GHz and/or with 4-bit table) does not depend on otherparameters, for example S={1, 2, 3, 4, ½, ¼, ⅛, reserved} or S={1, 2, 3,4, ½, ¼, ⅛, 1/16}.

In some embodiments, the table for 3-6 GHz (and/or single 8-bit bitmap)is different from the table for above or equal to 6 GHz (and/or two8-bit bitmaps). In some embodiments, the same table is used for bothcases, e.g. similarly as in Table 12.

Example Embodiments of the Number of Preambles Per SSB Per PRACHResource (P) Depending on S

In various embodiments, the total number of preambles per PRACH resourceis fixed or given by a specification, for example to 64. In someembodiments, it is configurable, e.g. to 64, 128 or 256. It is clearthat it is most efficient if the number of preambles per SSB per PRACHresource (P) falls within this number, e.g. up to 64. However, withmultiple SSBs associated with the same RACH resource and with the SSBsassociated with disjoint subsets of preamble indices, instead the totalnumber of preambles, summed over the SSBs associated with a RACHresource, should fall within this number. For example, if 8 SSBs areassociated with disjoint subsets in the same RACH resource, which hastotally 64 available preamble indices, then it doesn't make sense toassociate the SSBs to subsets of preamble indices with more than 8indices, since then the subsets couldn't be disjoint. On the other hand,if only a small number of SSBs are associated with a PRACH resource,e.g. 1 SSB, then it should be possible to associate it with a subset ofpreamble indices that is large, e.g. all available preamble indices inthe PRACH resource, e.g. 64. Hence, a more efficient indication of thenumber of preambles per SSB per PRACH resource (P) can be achieved ifthe value range of number of preambles per SSB per PRACH resource (P)depends on the configured number of SSBs per PRACH resource (S). For asmall S, larger values of P should be included in the value range of P.For a large S, smaller values of P should be included in the value rangeof P.

In an example, for S≤4: the value range of P=4*N, with N=1, . . . , 16and for S>4: the value range of P=4*N, with N=¼, ½, 1, . . . , 14.

In another example, for S≤4: the value range of P=4*N, with N=1, . . . ,16 and for S>4: the value range of P=N, with N=1, . . . , 16.

In yet another example, for S<4: the value range of P=4*N, with N=1, . .. , 16 and for S≥4: the value range of P=N, with N=1, . . . , 16.

FIG. 10 shows an example of a wireless communication method carried outon a wireless device (or user equipment). The method 1000 includes, atstep 1010, receiving, from a network node, at least one signalingparameter. In some embodiments, the at least one signaling parameter isreceived as part of a random access configuration. In other embodiments,the at least one signaling parameter comprises one or more of a numberof frequency multiplexed physical random access channel (PRACH)resources, a number of times a sequence is repeated within a preamble,the number of actually transmitted SSBs, the number of actuallytransmitted SSBs within a group of SSBs, or a number of consecutivePRACH resources.

The method 1000 includes, at step 1020, receiving a plurality ofdownlink signals. In some embodiments, the plurality of downlink signalscomprises SS/PBCH (synchronization signal/physical broadcast channel)blocks (SSBs), CSI-RS (channel-state information reference signal), oractually transmitted SSBs.

The method 1000 includes, at step 1030, generating measurements based onat least one of the plurality of downlink signals. In some embodiments,the measurements comprise reference signal received power (RSRP).

The method 1000 includes, at step 1040, selecting one of the pluralityof downlink signals based on the measurements.

The method 1000 includes, at step 1050, identifying a set of randomaccess resources and a set of random access preamble indexes associatedwith the one of the plurality of downlink signals based on the at leastone signaling parameter. In some embodiments, the set of random accessresources is identified from a larger set of random access resources,and wherein the set of random access preamble indexes is identified froma larger set of random access preamble indexes. In other embodiments,the identification of the set of random access resources and the set ofrandom access preamble indexes is performed as described in the contextof various embodiments disclosed in this patent document.

The method 1000 includes, at step 1060, selecting a random accessresource from the identified set of random access resources and a randomaccess preamble index from the identified set of random access preambleindexes.

The method 1000 includes, at step 1070, transmitting a preamble with theselected random access preamble index on the selected random accessresource.

FIG. 11 shows an example of a wireless communication method carried outon a network node (or gNB or base station). This example may includesome features and/or steps that are similar to those shown in FIG. 10,and described in this document. At least some of these features and/orcomponents may not be separately described in this section.

The method 1100 includes, at step 1110, transmitting, to a wirelessdevice, a random access configuration comprising at least one signalingparameter. In some embodiments, the at least one signaling parametercomprises a number of frequency multiplexed physical random accesschannel (PRACH) resources, a number of times a sequence is repeatedwithin a preamble, a number of actually transmitted SSBs, a number ofactually transmitted SSBs within a group of SSBs, or a number ofconsecutive PRACH resources.

The method 1100 includes, at step 1120, transmitting a plurality ofdownlink signals. In some embodiments, the plurality of downlink signalscomprises SS/PBCH (synchronization signal/physical broadcast channel)blocks (SSBs), CSI-RS (channel-state information reference signal), oractually transmitted SSBs.

The method 1100 includes, at step 1130, detecting a preamble with arandom access preamble index on a random access resource.

The method 1100 includes, at step 1140, transmitting, in response toreceiving the preamble, a random access response. In some embodiments,the random access resource and the random access preamble index areselected from a set of random access resources and a set of randomaccess preamble indexes, respectively, and wherein the selection isassociated with one of the plurality of downlink signals based on the atleast one signaling parameter.

The method 1100 may further include receiving, in response totransmitting the random access response, a connection request message.The method 1100 may further include transmitting, in response toreceiving the connection request message, a contention resolutionmessage to complete a configuration of a random access procedure forsubsequent data transmission between the network node and the wirelessdevice.

Another example of a wireless communication method, implemented at anetwork node, includes receiving, from a network node, an informationelement indicating a first parameter and a second parameter, selecting arandom access resource based on the first parameter, selecting a randomaccess preamble index based on the second parameter, wherein a value ofthe second parameter does not exceed a maximum value for the secondparameter based on a relationship between the first and secondparameter, and transmitting a preamble with the selected random accesspreamble index on the selected random access resource.

Yet another example of a wireless communication method, implemented at awireless device, includes transmitting, to a wireless device, aninformation element indicating a first parameter and a second parameter,transmitting a plurality of downlink signals, detecting a preamble witha random access preamble index on a random access resource, andtransmitting, in response to receiving the preamble, a random accessresponse, wherein the random access resource and the random accesspreamble index are selected from a set of random access resources and aset of random access preamble indexes, respectively, wherein theselection is associated with one of the plurality of downlink signalsbased on the first parameter and the second parameter, and wherein avalue of the second parameter does not exceed a maximum value for thesecond parameter based on a relationship between the first and secondparameter.

These methods may further include the first parameter beingSSB-per-rach-occasion, and the second parameter beingCB-preambles-per-SSB. In an example, the value of the second parameteris in a first range of values when the first parameter is less than athreshold value, and the value of the second parameter is in a secondrange of values different from the first range of values when the firstparameter is greater than or equal to the threshold value. In anotherexample, each value of the first range of values is a multiple of acorresponding value in the second range of values.

FIG. 12 is a block diagram representation of a portion of a radiostation, in accordance with some embodiments of the presently disclosedtechnology. An apparatus 1205, such as a base station or a wirelessdevice (or UE), can include processor electronics 1210 such as amicroprocessor that implements one or more of the techniques presentedin this document. The apparatus 1205 can include transceiver electronics1215 to send and/or receive wireless signals over one or morecommunication interfaces such as antenna(s) 1220. The apparatus 1205 caninclude other communication interfaces for transmitting and receivingdata. Apparatus 1205 can include one or more memories (not explicitlyshown) configured to store information such as data and/or instructions.In some implementations, the processor electronics 1210 can include atleast a portion of the transceiver electronics 1215. In someembodiments, at least some of the disclosed techniques, modules orfunctions are implemented using the apparatus 1205.

It is intended that the specification, together with the drawings, beconsidered exemplary only, where exemplary means an example and, unlessotherwise stated, does not imply an ideal or a preferred embodiment. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. Additionally, the use of “or” is intended to include“and/or”, unless the context clearly indicates otherwise.

Some of the embodiments described herein are described in the generalcontext of methods or processes, which may be implemented in oneembodiment by a computer program product, embodied in acomputer-readable medium, including computer-executable instructions,such as program code, executed by computers in networked environments. Acomputer-readable medium may include removable and non-removable storagedevices including, but not limited to, Read Only Memory (ROM), RandomAccess Memory (RAM), compact discs (CDs), digital versatile discs (DVD),etc. Therefore, the computer-readable media can include a non-transitorystorage media. Generally, program modules may include routines,programs, objects, components, data structures, etc. that performparticular tasks or implement particular abstract data types. Computer-or processor-executable instructions, associated data structures, andprogram modules represent examples of program code for executing stepsof the methods disclosed herein. The particular sequence of suchexecutable instructions or associated data structures representsexamples of corresponding acts for implementing the functions describedin such steps or processes.

Some of the disclosed embodiments can be implemented as devices ormodules using hardware circuits, software, or combinations thereof. Forexample, a hardware circuit implementation can include discrete analogand/or digital components that are, for example, integrated as part of aprinted circuit board. Alternatively, or additionally, the disclosedcomponents or modules can be implemented as an Application SpecificIntegrated Circuit (ASIC) and/or as a Field Programmable Gate Array(FPGA) device. Some implementations may additionally or alternativelyinclude a digital signal processor (DSP) that is a specializedmicroprocessor with an architecture optimized for the operational needsof digital signal processing associated with the disclosedfunctionalities of this application. Similarly, the various componentsor sub-components within each module may be implemented in software,hardware or firmware. The connectivity between the modules and/orcomponents within the modules may be provided using any one of theconnectivity methods and media that is known in the art, including, butnot limited to, communications over the Internet, wired, or wirelessnetworks using the appropriate protocols.

While this document contains many specifics, these should not beconstrued as limitations on the scope of an invention that is claimed orof what may be claimed, but rather as descriptions of features specificto particular embodiments. Certain features that are described in thisdocument in the context of separate embodiments can also be implementedin combination in a single embodiment. Conversely, various features thatare described in the context of a single embodiment can also beimplemented in multiple embodiments separately or in any suitablesub-combination. Moreover, although features may be described above asacting in certain combinations and even initially claimed as such, oneor more features from a claimed combination can in some cases be excisedfrom the combination, and the claimed combination may be directed to asub-combination or a variation of a sub-combination. Similarly, whileoperations are depicted in the drawings in a particular order, thisshould not be understood as requiring that such operations be performedin the particular order shown or in sequential order, or that allillustrated operations be performed, to achieve desirable results.

Only a few implementations and examples are described and otherimplementations, enhancements and variations can be made based on whatis described and illustrated in this disclosure.

What is claimed is:
 1. A method for wireless communication, comprising:receiving, by a wireless device from a base station, a Radio ResourceControl (RRC) signaling including an information element configuring arandom access procedure, wherein the information element indicating anumber of synchronization signal blocks per random access occasion and anumber of preambles per synchronization signal block, and wherein thenumber of preambles per synchronization signal block summed over thenumber of synchronization signal blocks per random access occasion isless or equal to 64; and transmitting a preamble from the wirelessdevice to the base station on a random access resource selected based onthe RRC signaling for the random access procedure.
 2. The method ofclaim 1, wherein the number of synchronization signal blocks per randomaccess occasion is denoted as S and the number of preambles persynchronization signal block is denoted as P, and wherein for S<4,P=4×N, N=1, . . . ,
 16. 3. The method of claim 2, wherein P isconfigured as a 4-bit parameter and S is configured as a 3-bitparameter.
 4. The method of claim 1, wherein the number ofsynchronization signal blocks per random access occasion is denoted as Sand the number of preambles per synchronization signal block is denotedas P, and wherein for S=4, P=N, N=1, . . . ,
 16. 5. The method of claim4, wherein P is configured as a 4-bit parameter and S is configured as a3-bit parameter.
 6. A method for wireless communication, comprising:transmitting, by a base station to a wireless device, a Radio ResourceControl (RRC) signaling including an information element configuring arandom access procedure, wherein the information element indicating anumber of synchronization signal blocks per random access occasion and anumber of preambles per synchronization signal block, wherein the numberof preambles per synchronization signal block summed over the number ofsynchronization signal blocks per random access occasion is less orequal to 64; and receiving a preamble by the base station from thewireless device on a random access resource for the random accessprocedure in response to the RRC signaling.
 7. The method of claim 6,wherein the number of synchronization signal blocks per random accessoccasion is denoted as S and the number of preambles per synchronizationsignal block is denoted as P, and wherein for S<4, P=4×N, N=1, . . . ,16.
 8. The method of claim 7, wherein P is configured as a 4-bitparameter and S is configured as a 3-bit parameter.
 9. The method ofclaim 6, wherein the number of synchronization signal blocks per randomaccess occasion is denoted as S and the number of preambles persynchronization signal block is denoted as P, and wherein for S=4, P=N,N=1, . . . ,
 16. 10. The method of claim 9, wherein P is configured as a4-bit parameter and S is configured as a 3-bit parameter.
 11. A wirelesscommunications apparatus comprising: a processor; and a memory includingprocessor executable code, wherein the processor executable code uponexecution by the processor configures the processor to: receive, from abase station, a Radio Resource Control (RRC) signaling including aninformation element configuring a random access procedure, wherein theinformation element indicating a number of synchronization signal blocksper random access occasion and a number of preambles per synchronizationsignal block, and wherein the number of preambles per synchronizationsignal block summed over the number of synchronization signal blocks perrandom access occasion is less or equal to 64; and transmit a preambleto the base station on a random access resource selected based on theRRC signaling for the random access procedure.
 12. The apparatus ofclaim 11, wherein the number of synchronization signal blocks per randomaccess occasion is denoted as S and the number of preambles persynchronization signal block is denoted as P, and wherein for S<4,P=4×N, N=1, . . . ,
 16. 13. The apparatus of claim 12, wherein P isconfigured as a 4-bit parameter and S is configured as a 3-bitparameter.
 14. The apparatus of claim 11, wherein the number ofsynchronization signal blocks per random access occasion is denoted as Sand the number of preambles per synchronization signal block is denotedas P, and wherein for S=4, P=N, N=1, . . . ,
 16. 15. The apparatus ofclaim 14, wherein P is configured as a 4-bit parameter and S isconfigured as a 3-bit parameter.
 16. An apparatus for wirelesscommunication, comprising: a processor; and a memory including processorexecutable code, wherein the processor executable code upon execution bythe processor configures the processor to: transmit, to a wirelessdevice, a Radio Resource Control (RRC) signaling including aninformation element configuring a random access procedure, wherein theinformation element indicating a number of synchronization signal blocksper random access occasion and a number of preambles per synchronizationsignal block, wherein the number of preambles per synchronization signalblock summed over the number of synchronization signal blocks per randomaccess occasion is less or equal to 64; and receive a preamble from thewireless device on a random access resource for the random accessprocedure in response to the RRC signaling.
 17. The apparatus of claim16, wherein the number of synchronization signal blocks per randomaccess occasion is denoted as S and the number of preambles persynchronization signal block is denoted as P, and wherein for S<4,P=4×N, N=1, . . . ,
 16. 18. The apparatus of claim 17, wherein P isconfigured as a 4-bit parameter and S is configured as a 3-bitparameter.
 19. The apparatus of claim 16, wherein the number ofsynchronization signal blocks per random access occasion is denoted as Sand the number of preambles per synchronization signal block is denotedas P, and wherein for S=4, P=N, N=1, . . . ,
 16. 20. The apparatus ofclaim 19, wherein P is configured as a 4-bit parameter and S isconfigured as a 3-bit parameter.